springboot 整合redis

1，准备

①，一个linux虚拟机，安装好docker，再安装redis镜像，然后启动redis容器

②，身为程序员linux不可不玩，而docker就是一个强有力的工具

③，springboot版本2.0.2.RELEASE

2，redis配置

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;

import java.time.Duration;

@EnableCaching
@Configuration
public class CacheConfig {

    @Bean
    public RedisCacheConfiguration redisCacheConfiguration(){
        RedisCacheConfiguration configuration = RedisCacheConfiguration.defaultCacheConfig();
        Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new
                Jackson2JsonRedisSerializer<Object>(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        // 将类型序列化到属性json字符串中
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        configuration = configuration.serializeValuesWith(RedisSerializationContext.SerializationPair.
                fromSerializer(jackson2JsonRedisSerializer))
                .entryTtl(Duration.ofDays(30));
        return configuration;
    }
}

3，application.properties 配置

spring.redis.host=192.168.43.28
spring.redis.port=6379

4，RedisCacheConfiguration 生效

//使用RedisCacheManager 用于创建cache	
@Bean
	public RedisCacheManager cacheManager(RedisConnectionFactory redisConnectionFactory,
			ResourceLoader resourceLoader) {
		RedisCacheManagerBuilder builder = RedisCacheManager
				.builder(redisConnectionFactory)
				.cacheDefaults(determineConfiguration(resourceLoader.getClassLoader()));
		List<String> cacheNames = this.cacheProperties.getCacheNames();
		if (!cacheNames.isEmpty()) {
			builder.initialCacheNames(new LinkedHashSet<>(cacheNames));
		}
		return this.customizerInvoker.customize(builder.build());
	}

//RedisCacheManager 创建cache的方法	
protected RedisCache createRedisCache(String name, @Nullable RedisCacheConfiguration cacheConfig) {
		return new RedisCache(name, cacheWriter, cacheConfig != null ? cacheConfig : defaultCacheConfig);
	}

5，RedisCache 创建缓存的流程

//①，根据一定的策略生成缓存的key
protected String createCacheKey(Object key) {

		String convertedKey = convertKey(key);

		if (!cacheConfig.usePrefix()) {
			return convertedKey;
		}

		return prefixCacheKey(convertedKey);
	}

//②，先尝试获取缓存
	public byte[] get(String name, byte[] key) {

		Assert.notNull(name, "Name must not be null!");
		Assert.notNull(key, "Key must not be null!");

		return execute(name, connection -> connection.get(key));
	}
//③，获取不到就执行目标方法，并将返回结果放入缓存
public void put(Object key, @Nullable Object value) {

		Object cacheValue = preProcessCacheValue(value);

		if (!isAllowNullValues() && cacheValue == null) {

			throw new IllegalArgumentException(String.format(
					"Cache '%s' does not allow 'null' values. Avoid storing null via '@Cacheable(unless=\"#result == null\")' or configure RedisCache to allow 'null' via RedisCacheConfiguration.",
					name));
		}

		cacheWriter.put(name, createAndConvertCacheKey(key), serializeCacheValue(cacheValue), cacheConfig.getTtl());
	}

6，获取缓存的过程

//①，根据一定的策略生成缓存的key
protected String createCacheKey(Object key) {

		String convertedKey = convertKey(key);

		if (!cacheConfig.usePrefix()) {
			return convertedKey;
		}

		return prefixCacheKey(convertedKey);
	}
//②，尝试根据可以获取对应的缓存
	@Override
	public byte[] get(String name, byte[] key) {

		Assert.notNull(name, "Name must not be null!");
		Assert.notNull(key, "Key must not be null!");

		return execute(name, connection -> connection.get(key));
	}
//③，获取成功则不执行目标方法，直接将缓存返回

7，缓存在redis的样子

①，注意，缓存的数据要带有缓存的类型，否则redis缓存反序列化成对应pojo会失败，只要按上面的CacheConfig配置好RedisCacheConfiguration 即可